Work

β-Alanine decreases plasma taurine but improves nitrogen utilization efficiency in beef steers

Year: 2025

Type: article

Abstract: Recent research has demonstrated that rumen-protected taurine supplementation improves body protein turnover, apparent nitrogen retention (ANR) and nitrogen (N) utilization efficiency (NUE) in beef steers. To further elucidate taurine's role in N metabolism, it is essential to examine whether taurine depletion adversely affects ANR and NUE. Six beef steers (bodyweight 391 ± 10 kg) were allocated in a replicated 3 × 3 Latin square design. Each experimental period was 20 d with 15 d for adaptation and 5 d for sampling. Three levels of rumen-protected β-alanine (RPβA, an inhibitor of taurine), i.e. 0, 17.5, or 35 g/d, were added to a basal diet to form the dietary treatments. The results showed that RPβA supplementations at 17.5 and 35 g/d linearly decreased the plasma taurine concentration ( P = 0.026) by 12.54% and 22.54%, and urinary taurine excretion ( P < 0.001) by 15.78% and 21.05%, respectively, while it linearly increased ANR ( P < 0.001) and NUE ( P < 0.001) in steers. RPβA supplementation linearly increased the plasma concentrations of methionine (Met) ( P < 0.001), lysine (Lys) ( P = 0.018), threonine (Thr) ( P = 0.011), leucine (Leu) ( P = 0.042) and histidine (His) ( P = 0.061), and the plasma concentrations of growth hormone ( P < 0.001), insulin-like growth factor-1 ( P < 0.001) and total antioxidant capacity ( P < 0.001). Rumen-protected β-alanine supplementation tended to decrease the skeletal muscle protein degradation rate ( P = 0.055). Supplementation with 35 g/d RPβA upregulated the plasma amino acid derivatives and oligopeptide, including N_linoleoyl_histidine ( P < 0.001), L_Met ( P < 0.001), L_4_chlorotryptophan ( P = 0.006), L_Thr ( P = 0.022), L_Lys ( P = 0.026), L_carnitine ( P = 0.038), suberic_acid ( P = 0.036), formyllysine ( P = 0.036), N_acetyltyrosine ( P = 0.042), histidylglycine ( P = 0.045) and N_formyl_L_glutamic_acid ( P = 0.047). Supplementation with 35 g/d RPβA also altered the muscle cell mRNA expression and upregulated the expressions of the hub genes, including GADPH , PFKM , TPII , PGK and PKM , while changing arginine and proline metabolism and the AMPK signaling pathways in beef steers. In conclusion, RPβA supplementation effectively reduced plasma taurine concentration while it improved ANR and NUE in steers. These effects were mediated through modulation of the plasma amino acid profile and metabolomic pathways, which appear to have counteracted the negative impacts of taurine depletion on N metabolism.

Source: Animal nutrition

DOI: 10.1016/j.aninu.2025.05.001

Authors: Shuo Zhang, Yufeng Liu, Jinming Hu, Cheng Liu, Mengmeng Li, Guangyong Zhao

Institutions: State Key Laboratory of Animal Nutrition, China Agricultural University

Language: English

Topic: Ruminant Nutrition and Digestive Physiology

Subfield: Agronomy and Crop Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $1,462